Transdermal patch drug delivery interactions with exercise

Quantitatively Predicting Effects of Exercise on Pharmacokinetics of Drugs Using a Physiologically Based Pharmacokinetic Model

Exercise significantly alters human physiological functions, such as increasing cardiac output and muscle blood flow and decreasing glomerular filtration rate (GFR) and liver blood flow, thereby altering the absorption, distribution, metabolism, and excretion of drugs. In this study, we aimed to establish a database of human physiological parameters during exercise and to construct equations for the relationship between changes in each physiological parameter and exercise intensity, including cardiac output, organ blood flow (e.g., muscle blood flow and kidney blood flow), oxygen uptake, plasma pH and GFR, etc. The polynomial equation P = ΣaiHRi was used for illustrating the relationship between the physiological parameters (P) and heart rate (HR), which served as an index of exercise intensity. The pharmacokinetics of midazolam, quinidine, digoxin, and lidocaine during exercise were predicted by a whole-body physiologically based pharmacokinetic (WB-PBPK) model and the developed database of physiological parameters following administration to 100 virtual subjects. The WB-PBPK model simulation results showed that most of the observed plasma drug concentrations fell within the 5th-95th percentiles of the simulations, and the estimated peak concentrations (Cmax) and area under the curve (AUC) of drugs were also within 0.5-2.0 folds of observations. Sensitivity analysis showed that exercise intensity, exercise duration, medication time, and alterations in physiological parameters significantly affected drug pharmacokinetics and the net effect depending on drug characteristics and exercise conditions. In conclusion, the pharmacokinetics of drugs during exercise could be quantitatively predicted using the developed WB-PBPK model and database of physiological parameters. SIGNIFICANCE STATEMENT: This study simulated real-time changes of human physiological parameters during exercise in the WB-PBPK model and comprehensively investigated pharmacokinetic changes during exercise following oral and intravenous administration. Furthermore, the factors affecting pharmacokinetics during exercise were also revealed.

The mother-offspring transfer of chlorothalonil through human breast milk: A multi-city cross-sectional study

4-Hydroxychlorothalonil (4-OH CHT), the main metabolite of chlorothalonil and the most widely used fungicide, has been frequently detected in human samples during monitoring. 4-OH CHT may exhibit higher toxicity and persistence in the environment compared to its prototype. In this study, a total of 540 paired serum and breast milk samples from pregnant women in three provinces in China were monitored for contaminant residues. 4-OH CHT was analyzed in the samples using ultra high-performance liquid chromatography - high-resolution mass spectrometry with a detection limit of 20 ng/L. The study investigated the effects of demographic factors, such as BMI, region of residence, and education level, on the levels of 4-OH CHT residues in serum and breast milk. Among the three provinces, the highest median concentration of 4-OH CHT in serum samples was observed in Hebei (1.04 × 103 ng/L), while the highest median concentration of 4-OH CHT in breast milk samples was observed in Hubei and Guangdong (491 ng/L). Multiple linear regression was used to investigate the significant positive correlation between 4-OH CHT in serum and breast milk (p = 0.000) after adjusting for personal characteristics. Based on this, the study further explored the influencing factors of transfer efficiencies (TEs) in conjunction with the individual TEs and the personal characteristics of the participants. Our results demonstrated that the age of the volunteers and their exercise habits had an effect on TEs, but further studies are needed to determine whether exercise leads to an increase in TEs.

Wheezing in tobacco farm workers in southern Brazil

BACKGROUND

Tobacco workers are exposed to several respiratory occupational sensitizers.

METHODS

A representative cross-sectional study was carried out on 2469 tobacco family farming growers. Gender-stratified multivariate analyses evaluated the association between wheezing and socio-demographic, behavioral, and occupational variables.

RESULTS

Wheezing prevalence was 11.0% with no difference between genders. Among men, age, smoking, strenuous work, pesticide use, contact with vegetable dust and dried tobacco dust, lifting sticks with tobacco leaves to the curing barns, and green tobacco sickness (GTS) were risk factors for wheezing. Among women, family history of asthma, tying hands of tobacco, strenuous work, contact with chemical disinfectants, and GTS were positively associated with wheezing. Harvesting lower tobacco leaves was a protective factor for the outcome in both genders.

CONCLUSIONS

Pesticides, dusts exposure, and GTS were risk factors for wheezing. The synergic effect of these factors needs to be better evaluated to improve prevention.

Acute effect of Snus on physical performance and perceived cognitive load on amateur footballers

Smokeless tobacco (Snus) is a substance that contains nicotine, which has been placed on World Anti-Doping Agency's 2014 Monitoring Program. A proliferation of nicotine use in sport has been observed in recent years, but little is known regarding its effects, especially on football players' performance. Therefore, the aim of this study was to assess the effect of Snus on physical performance, heart rate variability, subjective activation, mental fatigue, and perceived readiness before a physical test in non-smoker, non-Snus user, amateur football players. Participants were administered either Snus or placebo 40 min prior to a fitness test battery (handgrip test, countermovement jump, agility test, and Yo-Yo intermittent recovery test). Results showed that Snus intake (compared with placebo) increased perceived mental fatigue level and mental load, and reduced perceived readiness level and heart rate variability. No significant differences between the two experimental conditions were found in either performance in the physical tests or perceived physical fatigue levels. In light of these results, Snus could not be considered an ergogenic substance. On the contrary, based on the extant evidence linking mental load and fatigue with physical performance, we argue that the observed negative effects on mental fatigue, perceived readiness, and heart rate variability should be considered.

The effects of caffeine, nicotine, ethanol, and tetrahydrocannabinol on exercise performance

Caffeine, nicotine, ethanol and tetrahydrocannabinol (THC) are among the most prevalent and culturally accepted drugs in western society. For example, in Europe and North America up to 90% of the adult population drinks coffee daily and, although less prevalent, the other drugs are also used extensively by the population. Smoked tobacco, excessive alcohol consumption and marijuana (cannabis) smoking are addictive and exhibit adverse health effects. These drugs are not only common in the general population, but have also made their way into elite sports because of their purported performance-altering potential. Only one of the drugs (i.e., caffeine) has enough scientific evidence indicating an ergogenic effect. There is some preliminary evidence for nicotine as an ergogenic aid, but further study is required; cannabis and alcohol can exhibit ergogenic potential under specific circumstances but are in general believed to be ergolytic for sports performance. These drugs are currently (THC, ethanol) or have been (caffeine) on the prohibited list of the World Anti-Doping Agency or are being monitored (nicotine) due to their potential ergogenic or ergolytic effects. The aim of this brief review is to evaluate the effects of caffeine, nicotine, ethanol and THC by: 1) examining evidence supporting the ergogenic or ergolytic effects; 2) providing an overview of the mechanism(s) of action and physiological effects; and 3) where appropriate, reviewing their impact as performance-altering aids used in recreational and elite sports.

Topical glyceryl trinitrate treatment of chronic patellar tendinopathy: a randomised, double-blind, placebo-controlled clinical trial

OBJECTIVES

To assess if continuous topical glyceryl trinitrate (GTN) treatment improves outcome in patients with chronic patellar tendinopathy when compared with eccentric training alone.

METHODS

Randomised double-blind, placebo-controlled clinical trial comparing a 12-week programme of using a GTN or placebo patch in combination with eccentric squats on a decline board. Measurements were performed at baseline, 6, 12 and 24 weeks. Primary outcome measure was the Victorian Institute of Sports Assessment-Patella (VISA-P) questionnaire. Secondary outcome measures were patient satisfaction and pain scores during sports. Generalised estimated equation was used to analyse the treatment, time and treatment×time effect. Analyses were performed following the intention-to-treat principle.

RESULTS

VISA-P scores for both groups improved over the study period to 75.0±16.2 and 80.7±22.1 at 24 weeks. Results showed a significant effect for time (p<0.01) but no effect for treatment×time (p=0.80). Mean Visual Analogue Scores pain scores during sports for both groups increased over the study period to 6.6±3 and 7.8±3.1. Results showed a significant effect for time (p<0.01) but no effect for treatment×time (p=0.38). Patient satisfaction showed no difference between GTN and placebo groups (p=0.25) after 24 weeks, but did show a significant difference over time (p=0.01). Three patients in the GTN group reported some rash.

CONCLUSION

It seems that continuous topical GTN treatment in addition to an eccentric exercise programme does not improve clinical outcome compared to placebo patches and an eccentric exercise programme in patients with chronic patellar tendinopathy.